Parallels Desktop repeatedly blocked by Norton Security

Several times a day, Norton Security (with Backup) is blocking Parallels Desktop, despite the fact that Parallels Desktop allowed in the Applications Blocking list. When away from the mac it queues up numerous pop-up messages telling me that Parallels Desktop app is blocked. This makes Norton Security unusable when accessing the Windows 7 virtual machine remotely, and it is necessary to disable Application Blocking altogether. Anyone aware of a fix?

There are several similar threads on this topic which are locked without providing an answer.

OSX Yosemite 10.10.3
Parallels Desktop 10.2.0
Norton Security 6.2 build 85